1. Field of the Invention
The present invention relates to an even-level inverter that voltage-divides input DC power into an even number of voltage levels and generates AC output signals having the even number of voltage levels by using a plurality of switching devices, while reducing conduction loss and controlling reactive power by removing an anti-parallel diode from a bidirectional switching device and separating a center tap of a voltage-dividing circuit from the switching device.
2. Description of the Related Art
An inverter, a circuit outputting an AC signal after receiving DC power, may control the magnitude, frequency, and harmonic component of the output AC signal. In general, an inverter may be classified into a 2-level inverter, a 3-level inverter, and the like, according to a level (magnitude) of the output AC signal, and may include a circuit that voltage-divides the input DC power into the number of required levels and a switching circuit that generates the AC output signal from the input DC power which is voltage-divided into the number of required levels.
In a 3-level inverter, widely used in general, a circuit that voltage-divides the input DC power into three levels may be implemented by capacitors having the same capacity and a switching circuit may include a plurality of switching devices in which a transistor and a diode are connected to each other. In particular, in the inverter circuit according to the related art, a bidirectional switching device is connected to a center tap of a voltage-dividing circuit to provide a path required for an output signal according to each operating mode.
However, as described in the related art, since the related art inverter circuit has a structure in which the switching device is directly connected to a center tap of a voltage-dividing circuit, it is very difficult to control reactive power. Furthermore, since a transistor and an anti-parallel diode are included in all switching devices, conduction loss may be deteriorated.